The invention relates to new phosphole and diphosphole based ligands useful as polymerization catalysts.
The phosphole ring system is described by structure A. This structure is distinct from the class of compounds B which contain benzo rings fused to the phosphole core. 
Class I has a much different electronic structure and therefore has much different chemistry than compounds of class II. In class I, the P atom is part of the delocalized, partially aromatic ring system. In class II, the aromaticity is confined to the benzo rings, with no delocalization around the P atom. Class I will participate in Diels-Alder chemistry (especially when complexed to a metal) (Bhaduri et al., Organometallics 1992, 11, pp. 4069-4076), whereas compounds of class II will not (Quin, Compr. Heterocycl. Chem. II Bird, Clive W (Ed), 1996, Vol. 2, pp. 757-856).
Very few compounds have been reported that contain two phosphole rings connected via a bridge (A) between the phosphorus atoms (structure C) (A=bridging hydrocarbon, hydrocarbon/heteroatom(s), or organometallic group). 
One explanation for the paucity of compounds of type C-G is the lack of synthetic procedures broad enough in scope to prepare the phosphole ring system. 
Examples reported in the literature include the compounds 1 (Braye et al., Tetrahedron 1971, pp. 5523-37), 2 (A=xe2x80x94CH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, and xe2x80x94CHxe2x95x90CHxe2x80x94CHxe2x95x90CHxe2x80x94) (Charrier et al., Organometallics 1987, 6 pp. 586 91), and 3 (Gradoz et al., J. Chem. Soc. Dalton Trans. 1992, pp. 3047-3051). 
Compounds containing a single phosphole ring (I) were made using the Fagan-Nugent heterocycle synthesis (Fagan et al., J. Am. Chem. Soc. 1994, 116, pp. 1880-1889; Fagan et al., J. Am. Chem. Soc. 1988, 110, pp. 2310-2312). This synthesis involves preparing the zirconium reagents by coupling of acetylenes followed by transfer of the metallacycle from zirconium to phosphorus. In all cases, the substituent on the phosphorus was an aromatic group such as phenyl.
These types of compounds (containing a single phosphole ring) have found limited utility as ligands for transition metals for use in catalysis, and have been shown to have different chemistries than their phosphine analogs (Neibecker et al., New J. Chem. 1991, pp. 279-81; Neibecker et al., J. Mol. Catal. 1989, 57 pp. 153-163; Neibecker et al., J. Mol Catal. 1989, 219-227; Vac et al., Inorg. Chem. 1989 28, pp. 3831-3836; Hjortkjaer et al., J. Mol. Catal. 1989 50, 203-210).
Transition metal complexes have been made using structures of class VII, shown below, where the rings are linked at the position alpha to phosphorus. Attempts to use these ligands to make Pd acetonitrile complexes analogous to those in the instant invention failed (Guoygou et al., Organometallics 1997, 16, 1008-1015). 
Copolymers of carbon monoxide and olefins, such as ethylene, can be made by free radical initiated copolymerization (Brubaker, J. Am. Chem. Soc., 1952, 74, 1509) or gamma-ray induced copolymerization (Steinberg, Polym. Eng. Sci., 1977, 17, 335). The copolymers produced were random copolymers and their melting points were low. In 1951, Reppe discovered a nickel-catalyzed ethylene carbon monoxide copolymerization system that gave alternating copolymers (U.S. Pat. No. 2,577,208 (1951)). However, the molecular weights of these polymers were also low.
In 1984, U.S. Pat. Nos. 4,818,810 and 4,835,250 disclosed the production of alternating olefin carbon monoxide copolymers based on Pd(II), Ni(II) and Co(II) complexes bearing bidentate ligands of the formula R1R2Exe2x80x94Axe2x80x94Exe2x80x94R3R4, wherein R1, R2, R3, R4, and A are organic groups and E is phosphorus, arsenic, or antimony. When E is phosphorus and R1-4 are aryl groups, the corresponding diphosphine palladium complexes are active in copolymerizing ethylene and carbon monoxide to produce copolymers of molecular weight up to 30,000 (MWn) (Drent et al., Chem. Rev., 1996, 96, 663). No compounds were claimed or disclosed in which R1 and R2, and R3 and R4 together formed a ring. Applicants have recently found that the diphosphole coordinated palladium catalysts catalyze olefin/carbon monoxide (CO) copolymerization. When the P atom is part of a ring system, the electronic environment and therefore expected chemistries are different than simple, non-ring phosphine disclosed in the patents described above.
Radical polymerization is an important commercial process for making a variety of polymers of vinyl monomers, such as acrylics and styrenics. While this process makes large amounts of polymers, the difficulty in accurately controlling the polymer structures (such as molecular weight, molecular weight distribution, and architecture, etc.) has significantly limited its further applications.
Living polymerization usually offers much better control on polymer structures and architectures. While living polymerization systems for anionic, cationic, and group transfer mechanisms were developed some years ago, a true living radical polymerization system is still an elusive goal (because of the high reactivity of free radicals) and only very recently has pseudo-living radical polymerization been achieved. One pseudo-living radical polymerization method is xe2x80x9catom transfer radical polymerizationxe2x80x9d (ATRP). In this process a transition metal compound, usually in a lower valent state, is contacted with a compound which is capable of transferring an atom to the metal complex, thereby oxidizing the metal to a higher valent state and forming a radical which can initiate polymerization. However, the atom that was transferred to the metal complex may be reversibly transferred back to the growing polymer chain at any time. In this way, the propagation step is regulated by this reversible atom transfer equilibrium and statistically all polymer chains grow at the same rate. The results a pseudo-living radical polymerization in which the molecular weight may be closely controlled and the molecular weight distribution is narrow.
Such ATRPs are described in many publications (Kato et al., Macromolecules 1995, 28, 1721; Wang et al., Macromolecules 1995, 28, 7572; Wang et al., Macromolecules 1995, 28, 7901; Granel et al., Macromolecules 1996, 29, 8576; Matyjaszewski et al., PCT WO 96/30421). The transition metal complexes used include complexes of Cu(I), Ru(II), Ni(II), Fe(II), and Rh(II). The complexes are formed by coordinating the metal ions with certain ligands such as nitrogen or phosphine containing ligands. For Ru(II) and Fe(II), mono-phosphine P(C6H5)3 was used as the ligand. However, for Cu(I), all the ligands used are nitrogen-based such as bipyridine or substituted bipyridine. No phosphine-based ligand has been shown to be an effective ligand for Cu(I) in ATRP.
It has been found that novel types of ligands containing phosphole and other P ring systems can chelate Cu(I) to form active catalysts for ATRP.
An object of this invention is to provide a process for the preparation of compounds of formulae I and II 
by reacting a compound of formula X2Pxe2x80x94Axe2x80x94PX2 (III) with a compound of formula IV; 
wherein R1, R2, R3 and R4 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl; R2 and R3 together can optionally form a ring; Cp is cyclopentadienyl; X is selected from the group consisting of Cl, Br, and I; A is a divalent group consisting of optionally-substituted chains of from 1 to 12 linear, branched, or cyclic carbons, optionally containing one or more heteroatoms or organometallic groups in the chain, and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94; and R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl.
Preferably A is selected from the group consisting of a carbon chain of 1-3 carbons and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94, wherein R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl. More preferably R1, R2, R3 and R4 are alkyl groups.
The invention also provides for a compound of the formula 
wherein R1, R2, R3 and R4 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl; R5 and R6 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, Cl, Br, I, N, O and S; R2 and R3 together and R5 and R6 together can optionally form a ring; Cp is cyclopentadienyl (xcex75xe2x80x94C5H5); A is a divalent group consisting of optionally-substituted chains of from 1 to 12 linear, branched, or cyclic carbons, optionally containing one or more heteroatoms or organometallic groups in the chain, and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94; and R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl.
Preferably A is selected from the group consisting of a carbon chain of 1-3 carbons and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94, wherein R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl. More preferably R1, R2, R3 and R4 are alkyl groups and R5 and R6 are selected from the group consisting of alkyl groups and Cl.
A further object of the invention is a coordination compound comprising one or more transition metals complexed to one or more of the following compounds as ligands: 
wherein R1, R2, R3 and R4 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl; R5 and R6 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, Cl, Br, I, N, O and S; R2 and R3 together and R5 and R6 together can optionally form a ring; A is a divalent group consisting of optionally-substituted chains of from 1 to 12 linear, branched, or cyclic carbons, optionally containing one or more heteroatoms or organometallic groups in the chain, and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94; and R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl.
Preferably the transition metal is Pd and A is selected from the group consisting of a carbon chain of 1-3 carbons and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94, wherein R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl. More preferably R1, R2, R3, and R4 are alkyl groups and R5 and R6 are selected from the group consisting of alkyl groups and Cl.
The invention also provides a process for the preparation of a polyketone by contacting a mixture of carbon monoxide with one or more alkenes under polymerization conditions with a catalyst comprising a transition metal complexed with one or more ligands of the formulae IIA or VA 
wherein the rings are optionally-substituted and are optionally members of a larger bicyclic or tricyclic ring system; each P atom is bonded to only three other atoms in the ligand; the two atoms in the ring adjacent to the P atom are C atoms; R5 and R6 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, Cl, Br, I, N, O, and S; R5 and R6 together can optionally form a ring; A is a divalent group consisting of optionally-substituted chains of from 1 to 12 linear, branched, or cyclic carbons, optionally containing one or more heteroatoms or organometallic groups in the chain, and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94; and R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl.
Preferably the transition metal is Pd and the ligand is of the formulae V or II 
wherein R, R2, R3, and R4 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl; R5 and R6 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, Cl, Br, I, N, O, and S; R2 and R3 together and R5 and R6 together can optionally form a ring; A is a divalent group consisting of optionally-substituted chains of from 1 to 12 linear, branched, or cyclic carbons, optionally containing one or more heteroatoms or organometallic groups in the chain, and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94; and R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl. More preferably A is selected from the group consisting of a carbon chain of 1-3 carbons and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94, R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl R1, R2, R3, and R4 are alkyl groups, R5 and R6 are selected from the group consisting of alkyl groups and Cl, and the alkene is ethylene.
Another object of the invention is a process for the polymerization of an acrylic monomer by contacting at least one acrylic monomer under polymerization conditions with a catalyst comprising Cu(I) complexed with one or more ligands of the formulae IIA or VA 
wherein the rings are optionally-substituted and are optionally members of a larger bicyclic or tricyclic ring system; each P atom is bonded to only three other atoms in the ligand; the two atoms in the ring adjacent to the P atom are C atoms; R5 and R6 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, Cl, Br, I, N, O, and S; R5 and R6 together can optionally form a ring; A is a divalent group of optionally-substituted chains of from 1 to 12 linear, branched, or cyclic carbons, optionally containing one or more heteroatoms or organometallic groups in the chain, and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94; and R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl.
Preferably the ligand is of the formulae V or II 
wherein R1, R2, R3, and R4 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl; R5 and R6 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, Cl, Br, I, N, O, and S; R2 and R3 together and R5 and R6 together can optionally form a ring; A is a divalent group consisting of optionally-substituted chains of from 1 to 12 linear, branched, or cyclic carbons, optionally containing one or more heteroatoms or organometallic groups in the chain, and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94; and R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl. More preferably A is selected from the group consisting of a carbon chain of 1-3 carbons and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94, wherein R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl, R1, R2, R3, and R4 re alkyl groups, R5 and R6 are selected from the group consisting of alkyl groups and Cl, and the acrylic monomer is methylmethacrylate.
This invention provides novel reactions used to prepare phosphole and bisphosphole compounds. Novel phosphole compounds and metal coordination compounds of phosphole and bisphosphole compounds are also provided. These metal coordination compounds are useful as polymerization catalysts.
The present invention provides processes for the preparation of bisphosphole compounds of formulae I and II 
by reacting a compound of formula IV with a compound of formula X2Pxe2x80x94Axe2x80x94PX2 (III); 
wherein:
R1, R2, R3, and R4 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl;
R2 and R3 together can optionally form a ring;
Cp is cyclopentadienyl (xcex75xe2x80x94C5H5);
X is selected from the group consisting of Cl, Br, and I;
A is a divalent group consisting of optionally-substituted chains of from 1 to 12 linear, branched, or cyclic carbons, optionally containing one or more heteroatoms or organometallic groups in the chain, and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94; and
R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl.
By hydrocarbyl is meant a straight chain, branched or cyclic arrangement of carbon atoms connected by single, double, or triple carbon to carbon bonds and/or by ether linkages, and substituted accordingly with hydrogen atoms. Such hydrocarbyl groups may be aliphatic and/or aromatic. Examples of hydrocarbyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, cyclopropyl, cyclobutyl, cyclopentyl, methylcyclopentyl, cyclohexyl, methylcyclohexyl, benzyl, phenyl, o-tolyl, m-tolyl, p-tolyl, xylyl, vinyl, allyl, butenyl, cyclohexenyl, cyclooctenyl, cyclooctadienyl, and butynyl. Examples of substituted hydrocarbyl groups include toluyl, chlorobenzyl, fluoroethyl, pxe2x80x94CH3xe2x80x94Sxe2x80x94C6H5, 2-methoxy-propyl, and (CH3)3SiCH2.
xe2x80x9cCoordination compoundxe2x80x9d refers to a compound formed by the union of a metal ion (usually a transition metal) with a non-metallic ion or molecule called a ligand or complexing agent.
Preferred compounds of formulae II and I include those where A is selected from the group consisting of xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94 and carbon chains of 1-3 carbons. Also preferred are compounds of formulae III and W where R1, R2, R3, and R4 are alkyl groups. Most preferred are 1,2-bis(2,3,4,5-tetramethylphospholyl)ethane; 1,2-bis(2,3,4,5-tetraethylphospholyl)ethane; 1,1-bis(2,3,4,5-tetramethylphospholyl)methane; 1,1-bis(2,3,4,5-tetraethylphospholyl)methane; 1,2-bis(2,3,4,5-tetramethylphospholyl)-1,2-dimethylhydrazine; 1-(2,3,4,5-tetramethylphospholyl)-2-dichlorophosphinoethane; and 1-(2,3,4,5-tetramethylphospholyl)-2-dichlorophosphinoethane-1,2-dimethylhydrazine.
The process can be run in a wide variety of solvents. Preferred solvents are CH2Cl2 and THF (tetrahydrofuran). Low temperatures, below from about xe2x88x92100xc2x0 C. to room temperature, are typically used.
The zirconium reagents (IV) are first prepared by reacting Cp2ZrCl2 (Cpxe2x95x90xcex75xe2x80x94C5H5, cyclopentadienyl) with n-BuLi at about xe2x88x9278xc2x0 C. followed by warming in the presence of an alkyne, alkynes, or dialkyne. The metallacycles can be isolated, or used in situ. When these are reacted with one-half of a molar equivalent of a diphosphorus compound X2Pxe2x80x94Axe2x80x94PX2, compounds of formula II result (Scheme 1). 
If zirconium metallacycles of type IV are reacted with at least one equivalent of the phosphorus reagents X2Pxe2x80x94Axe2x80x94PX2, then compounds of formula I can be prepared (Scheme 2). 
Dialkynes provide zirconium metallacycles of formula IVA which can be reacted with X2Pxe2x80x94Axe2x80x94PX2 to form compounds of formula II wherein R2 and R3 together form a ring as illustrated in Scheme 3. 
where Z is any linking group with proper orientation or is flexible enough to allow the reaction to proceed. Examples of suitable linking groups include hydrocarbyl, substituted hydrocarbyl, and organometallic compounds. Preferred is xe2x80x94(CH2)xxe2x80x94, where X is 1-10.
The above reactions should be performed under a N2 atmosphere using anhydrous solvents.
Similarly, the products from reaction of zirconium metallacycles IVA allows the corresponding compounds of formula I wherein R2 and R3 together form a ring to be prepared (Scheme 4). 
The present invention also provides for novel phosphole compositions of the formula V 
wherein R1, R2, R3, and R4 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl;
R5 and R6 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, Cl, Br, I, N, O, and S;
R2 and R3 together and R5 and R6 together can optionally form a ring;
A is a divalent group consisting of optionally-substituted chains of from 1 to 12 linear, branched, or cyclic carbons, optionally containing one or more heteroatoms or organometallic groups in the chain, and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94; and
R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl.
Preferred compounds of formulae V include those where A is selected from the group consisting of xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94 and carbon chains of 1-3 carbons. Also preferred are compounds of formulae V where R1, R2, R3, and R4 are alkyl groups, and where R5 and R6 are hydrocarbyl, substituted hydrocarbyl, alkoxy, Cl, Br, and I. Most preferred are 1-(2,3,4,5-tetramethylphospholyl)-2-dichlorophosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-dichlorophosphinoethane-1,2-dimethylhydrazine; [2-(tetramethylphospholyl)ethyl]-[(R,R)-2,7-dimethyl-3,6-decadiyl]phosphine; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(4-methylphenyl)-phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(4-chlorophenyl)-phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(4-tert-butylphenyl)-phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-diethynylphosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(n-propynyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(4-fluorophenyl)phosphinoethane; 1-(2,3,4,5-tetra-methylphospholyl)-2-di-(phenylethy 1-(2,3,4,5-tetramethylphospholyl)-2-divinylphosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-dicyclopentylphosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(n-decyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(4-fluoro-3-methylphenyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(3,4-difluorophenyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(4-butylphenyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(3-fluoro-2-methylphenyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(2-naphthyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(4-methyl-thiophenyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(3-methoxyphenyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(3-fluoro-4-methylphenyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(2-methoxyphenyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(4-methoxyphenyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(4-phenoxyphenyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-[4-(dimethylamino)phenyl]phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(2,4-difluorophenyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-(2,4,6-trimethylphenyl)phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-isopropenylphosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-diallyl-phosphinoethane; 1-(2,3,4,5-tetramethylphospholyl)-2-di-trimethylsilylmethyl-phosphinoethane; and 1-(2,3,4,5-tetramethylphospholyl)-2-di-[2-[1,3]dioxan-2-yl-ethyl]phosphinoethane.
Compounds of formula V where X is Cl, Br, or I can be prepared as detailed above. Other compounds of formula V can be prepared using compounds of formula I as an intermediate (Scheme 6). 
wherein R1, R2, R3, R4, R5, R6, R7, R8, A, and Z are as defined above, R9 and R10 are selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl;
M is any metal; and
R2 and R3 together and R5 and R6 together can optionally form a ring.
An alternative route to compounds of formula V and other compounds is the synthetic sequence shown in Scheme 7. 
Alternate syntheses can be used to prepare bis(phosphole) compounds of formulae II from compounds previously detailed above (Scheme 8). 
Another aspect of the present invention provides for novel coordination compounds comprising one or more transition metals complexed to one or more compounds of formulae V or II 
wherein R1, R2, R3, and R4 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl;
R5 and R6 are independently selected from the group consisting of hydrogen, hydrocarbyl, substituted hydrocarbyl, Cl, Br, I, N, O and S;
R2 and R3 together and R5 and R6 together can optionally form a ring;
A is a divalent group consisting of optionally-substituted chains of from 1 to 12 linear, branched, or cyclic carbons, optionally containing one or more heteroatoms or organometallic groups in the chain, and xe2x80x94N(R7)xe2x80x94N(R8)xe2x80x94; and
R7 and R8 are independently selected from the group consisting of hydrogen, hydrocarbyl, and substituted hydrocarbyl.
The transition metals are hereby defined as metals of atomic weight 21 through 83. Preferred metals are those of Cu(I) or of Periodic Group VIII, hereby defined as Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, and Pt. Most preferred is Pd.
Reactions to form coordination compounds use either a well-defined palladium catalyst such as [(diphosphole)PdMe(CH3CN)]SbF6 or catalysts generated in situ by mixing the diphospole ligand with palladium salts such as [Pd(CH3CN)4](BF4)2 or Pd(OAc)2. Catalysts prepared in situ were made from 1,2-bis(2,3,4,5-tetramethylphospholyl)ethane and Pd(OAc)2 and from 1,3-bis(2,3,4,5-tetraethylphospholyl)propane and [Pd(CH3CN)4(BF4)2. Preferred coordination compounds are [1,2-bis(2,3,4,5-tetramethylphospholyl)-ethane]PdMeCl; {[1,2-bis(2,3,4,5-tetramethylphospholyl)ethane]-PdMe(CH3CN)}SbF6; [1,2-bis(2,3,4,5-tetramethylphospholyl)-1,2-dimethyl-hydrazine]PdMeCl; and {[1,2-bis(2,3,4,5-tetramethylphospholyl)-1, 2-dimethylhydrazine]PdMe(CH3CN)}SbF6.
Coordination compounds made in the instant invention can be used as catalysts for olefin/carbon monoxide polymerizations. The olefin can be an alkene or a cycloalkene containing 2-30, preferably 2-12, carbon atoms. Examples of suitable alkenes can include ethylene, propylene, any isomeric butene, pentene, hexene, octene, and dodecene, cyclooctene, cyclododecene, styrene, methylstryene, acyrlic acid, methacrylic acid, alkyl esters of acrylic and metacylic acids, and dialkenes in which the two unsaturated groups are not conjugated.
Any suitable method to prepare polymer from carbon monoxide and an olefin using the instant catalysts can be used. The catalysts themselves can be isolated before polymerization or generated in situ. Preferred catalysts for this process contain Pd.
The ligands made in the instant invention can also be used to prepare Cu(I) coordination compounds, which are useful as catalysts in ATRP (atom transfer radical polymerization) processes, as defined above, to polymerize acrylic monomers. The acrylic monomers are of the formula 
where R1 is hydrogen, alkyl, or substituted alkyl group, and R2 is hydrogen, hydrocarbyl or substituted hydrocarbyl. Preferred are compounds where R1 is hydrogen, methyl or ethyl and R2 is hydrogen or methyl. Most preferred is where R1 and R2 are both methyl (methylmethacrylate).
Any suitable method to prepare the acrylic polymers using the instant catalysts can be used. The catalysts themselves can be isolated before polymerization or generated in situ. Preferred catalysts are those formed in situ from 1,2-bis(2,3,4,5-tetramethylphospholyl)-ethane and CuCl.
The following non-limiting Examples are meant to illustrate the invention but are not intended to limit it in any way.
Abbreviations used hereafter are listed and defined below as follows:
DSCxe2x80x94Differential scanning calorimetry
GPCxe2x80x94Gel Permeation chromatography
HFIPxe2x80x941,1,1,3,3,3-Hexafluoroisopropanol
CODxe2x80x941,5-Cyclooctadiene
FIDxe2x80x94Flame ionization detection
ATRPxe2x80x94Atom transfer radical polymerization
MMAxe2x80x94Methyl methacrylate
ECOxe2x80x94Ethylene/carbon monoxide
All manipulations of air-sensitive materials were carried out with rigorous exclusion of oxygen and moisture in flame-dried Schlenk-type glassware on a dual manifold Schlenk line, interfaced to a high-vacuum (10xe2x88x924-10xe2x88x925 Torr) line, or in a nitrogen-filled Vacuum Atmospheres glovebox with a high-capacity recirculator (1-2 ppm of O2). Before use, all solvents were distilled under dry nitrogen over appropriate drying agents (sodium benzophenone ketyl, metal hydrides except for chlorinated solvents). Deuterium oxide and chloroform-d were purchased from Cambridge Isotopes (Andover, Mass.). All organic starting materials were purchased from Aldrich Chemical Co., Farchan Laboratories Inc. (Kennett Square, Pa.), or Lancaster Synthesis Inc. (Windham, N.H.), and when appropriate were distilled prior to use. The substrate zirconium metallacycle (xcex75xe2x80x94C5H5)2ZrC4Me4, 2,3,4,5-tetramethylphospholylchloride were synthesized according to literature procedures. The substrates zirconium metallacycles (xcex75xe2x80x94C5H5)2ZrC4Et4, (xcex75xe2x80x94C5H5)2Zr(Me3Cxe2x80x94CCCH2CH2CH2CCxe2x80x94CMe3), and, 2,3,4,5-tetraethylphos-pholylchloride, 1,7-ditertbutyl-1, 6-bicyclo[3,3]heptadiynyl-phospholylchloride were synthesized via modifications of literature methods as described below.
NMR spectra were recorded on either a Nicolet NMC-300 wide-bore (FT, 300 MHz, 1H; 75 MHz, 13C, 121 MHz 31P), or GE QM-300 narrow-bore (FT, 300 MHz, 1H) instrument. Chemical shifts (xcex4) for 1H, 13C are referenced to internal solvent resonances and reported relative to SiMe4. 31P NMR shifts are reported relative to external phosphoric acid. Analytical gas chromatography was performed on a Varian Model 3700 gas chromatograph with FID detectors and a Hewlett-Packard 3390A digital recorder/integrator using a 0.125 in. i.d. column with 3.8% w/w SE-30 liquid phase on Chromosorb W support. GC/MS studies were conducted on a VG 70-250 SE instrument with 70 eV electron impact ionization. Melting points and boiling points are uncorrected.